Reading the release notes of the sdk and/or the MSDN pages used to be a great resource, and probably still is, but it's difficult to find new gems.

https://leanpub.com/practical-functional-csharp

https://prodotnetmemory.com/

https://www.oreilly.com/library/view/c-12-in/9781098147433/c...

https://learn.microsoft.com/en-us/dotnet/core/whats-new/

https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/

Can also recommend reading:

https://learn.microsoft.com/en-us/dotnet/core/tools/ (CLI, it's good)

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/m...

https://typescript-is-like-csharp.chrlschn.dev/pages/interme...

> are there books specifically about using .NET Core on Linux

There is nothing particular to using ".NET on Linux" - it just works. Standard Linux caveats not specific to .NET apply.